We will look at some Linux commands which will help us monitor system performance, gather statistics and view historical resource usage. Monitoring connections with ss command ss should be preinstalled for most modern Linux distributions Show established TCP connection ss -t Show established UDP connections ss -u Show ports listening for TCP connections ss -ltn…

We will take a look at hot to install SoftEther VPN on CentOS 7 and connect to it from Windows system running VPN manager. 1. We install CentOS 7 minimal with firewalld and selinux disabled. Make sure gcc is installed with all updates yum update -y yum install gcc 2. Download softether-vpnserver* package for Linux…

We are setting up replication of snapshots for backup purposes on FreeNAS. We setup Ubuntu server and install ZFS on it. We will use this system to receive snapshot for backup purposes. We manually generated ssh key on FreeNAS. This was done by connecting to CLI and running commands below. ssh-keygen -q -t rsa scp…

This article will show how to integrate Windows 2012 R2 Domain with CentOS 7 or RedHat 7. After completing this steps user will be able to login to Linux system with windows AS credentials. Installing Identity Management for UNIX on Windows 2012 R2 DC by using a command line Run powershell as administrator and execute…

Lets take a look at how to share existing ssh session using command called screen. It is very useful in case where you have to show your users something remotely. First install screen program – We assume CentOS7 yum install screen System1 You can create multiple screen sessions or share existing on Create multiple screen…

In some cases you want to change default email address of anonymous@hostname from which Nagios sends notifications. This can easily be done by changing following directives in Nagios configuration files. 1. Open the main Nagios configuration file nagios.cfg and edit the line containing admin_email vim nagios.cfg admin_email=nagios@localhost # change to your desired smtp address 2….